Furnace trays



M. N. ORNITZ FURNACE TRAYS March 13, 1962 2 Sheets-Sheet 1 Filed Sept.10, 1958 F ig.l.

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INVENTOR. Martin N. Omiiz BY zQ Z M A ATTORNEYS March 13, 1962 M. N.ORNITZ 3,025,045

FURNACE TRAYS Filed Sept. 10, 1958 2 Sheets-Sheet 2.

INVENTOR. Martin N. Ornitz ATTORNEYS.

Unite I States Patent Ofilice 3,025,045 Patented Mar. 13, 1962 awareFiled Sept. 10, 1958, Ser. No. 760,267 5 Claims. (Cl. 263-47) Thisinvention relates to furnace trays and particularly to trays forcarrying articles to be annealed or heat treated through annealing orheat treating furnaces, as, for example, continuous furnaces havingdoors at each end and rails or rollers therein to support and carry thetrays bearing the articles to be treated for passage through thefurnace. The trays may be moved through the furnace in series, the doorsbeing opened to admit a new tray and to remove the finally heated tray.Generally, the trays leaving the furnace pass through a water or an airquench. The trays are thus subject to severe thermal shock and arelikely to fracture due to the high thermal stresses which occur in theseveral parts of the tray. My construction is also useful for immovablework supporting trays in other types of heat treating furnaces.

Annealing and heat treating trays have heretofore been used. Such traysare generally made in the form of a grill or a grating integrally castof a heat resisting steel. Such trays are very susceptible to failuredue to the aforementioned thermal shock. Modifications of suchintegrally cast structure have been proposed in which intersectingmembers may move differentially in an effort to overcome the problem offailure from thermal shock. For example, Menough Patent 2,710,746provides a construction in which the intersecting members are notrigidly secured together.

The present invention provides a structure differing from the prior artstructures and having a unique articulated construction of simple,effective, inexpensive form relatively free at the joints between themembers. In the present invention, the members are free to independentlyundergo such thermal deflection as may be imposed on them in service,yet the structure is strong, durable, simple and easy to assemble, sothat the cost is low.

I provide a plurality of spaced substantially parallel primary elements,each having openings therethrough, a plurality of spaced substantiallyparallel cross elements disposed transversely to the primary elementsand extending through the openings in the primary elements, the crosselements being notched at spaced intervals along their lengths wherebythe notches engage portions of the primary elements adjacent theopenings therein, and keeper means secured in some of said openingswhereby the cross elements are restrained from substantial verticalmovement and hence are held in fixed relationship with the primaryelements.

Preferably, the keeper means are secured in at least two of the openingsfor each cross element whereby the elements are substantially restrainedfrom vertical movement. The slots are preferably wider at a portionthereof whereby the cross tie elements may enter initially through suchwider portion and then fit within the narrower portion with the notchesin the cross tie elements embracing a portion of the sides adjacent theslots of the narrower portions in loose interlocking engagements, andthe keeper means is secured in at least two of the wider portions of theslots.

In the foregoing general description, I have set out certain objects,advantages and purposes of the present invention. Other objects,advantages and purposes will be apparent from a consideration of thefollowing description and the accompanying drawings illustrating apreferred embodiment in which- FIGURE 1 is a top plan View of a furnacetray according to my invention;

FIGURE 2 is a side FIGURE 1;

FIGURE 3 is an FIGURE 1;

7 FIGURE 4 is an isometric view of a segment of the tray of FIGURE 1;and

FIGURE 5 is a segmental section on the line VV of FIGURE 1.

Referring to the drawings, I have illustrated a furnace tray having aplurality of spaced substantially parallel primary or load bearingelements 10, each having spaced slots or openings 11 therein. Each slot11 is provided with a wider main portion 11a and a narrower adjacentoffset portion 1112 so as to form an L-shape. A plurality of spacedsubstantially parallel cross elements 12 are inserted in the slots 11.The cross elements 12 are inserted through the widermain portion 11a ofslot 11 until notches 13 in cross elements 12 overlie the narrowerotfset portion 11b of slot 11. The cross elements 12 then dropdownwardly so that the notch 13 is in engagement with the step formingthe narrower offset portion 11b of the slot. A short bar 14 is insertedin the wider main portion 11a of the slot 11 and is welded in place toact as a keeper for the cross elements 12. The cross elements 12 arethus held in interlocking relation in the load bearing elements but arefree for movement within the smaller portion offset 11b of the slot 11.

In the embodiment shown in the drawings the load bearing elements 10 aregenerally symmetrical in section with the slots 11 spaced substantiallyalong their neutral axes, so that the trays are bodily reversible andeither side may be the load supporting side. In service they arereversed from time to time as deflections and sags develop due to creepof the alloy material of which they are made, and in such reversedposition the trays are self-straightening with respect to deflectionsformed while in their original position. This feature is preferred inmost cases but my articulated tray construction is not limited to usewith symmetrical elements or reversible trays.

It will be understood that, while I have illustrated and described apresently preferred embodiment of my invention, the invention may beotherwise embodied within the scope of the following claims.

I claim:

1. A furnace tray comprising a plurality of spaced substantiallyparallel primary elements, each having openings therethrough each ofsaid openings having a main portion and an offset portion on one sidethereof, a plurality of spaced substantially parallel cross elementsdisposed transversely to the primary elements and extending through theopenings in the primary elements, the cross elements being notched atspaced intervals along their lengths, said cross elements being sodisposed that the notched portions of the cross element lie in theoffset portions of the openings and the notches engage portions of theprimary elements adjacent the openings therein, and keeper means whoselength is short of and out of contact with the next adjacent primaryelements and which are free of the cross elements secured in some ofsaid openings to retain the notches in engagement with the primaryelements, whereby the cross elements are restrained from removal fromthe openings and are simultaneously free to move in loosely fittingfixed relationship with the primary elements.

2. A furnace tray comprising a plurality of spaced substantiallyparallel primary elements, each having slots therein at spacedintervals, said slots each having a main elevation of the tray of endelevation of the tray of portion and an offset portion on one sidethereof, a plurality of spaced substantially parallel cross elementsdisposed at substantially right angles to the primary elements andextending through the slots therein, the cross elements having notchesdisposed at spaced intervals along their lengths, said cross elementsbeing so disposed that the notched portions lie in the offset portion ofthe slots and the notches interlock with the portions of the primaryelements adjacent the slots, and keeper means whose length is short ofand out of contact with the next adjacent primary elements and which arefree of the cross elements secured in at least two of the slots for eachcross element retaining the notches in engagement with the primaryelements whereby the cross elements are substantially restrained fromremoval from the slots and are simultaneously free to move in loosefitting fixed relationship with the primary elements.

3. A furnace tray comprising a plurality of spaced substantiallyparallel load bearing elements, each having therethrough a plurality ofslots at spaced intervals along their lengths, said slots each having amain portion and an offset portion on one side thereof a plurality ofspaced substantially parallel cross tie elements disposed atsubstantially right angles to the load bearing elements and extendingthrough the slots therein, the cross tie elements being notched atspaced intervals along their lengths, said cross tie elements being sodisposed that the notched portions lie in the offset portion of theslots and the notches embrace the load bearing elements adjacent theslots therein in an interlocking engagement, and keeper means whoselength is short of and out of contact with the next adjacent primaryelements and which are free of the cross elements secured in at leasttwo of the slots for each cross element retaining the notches inengagement with the primary elements whereby the cross elements aresubstantially restrained from removal from the slots and aresimultaneously free to move in loose fitting fixed relationship with theload bearing elements.

4. A reversible furnace tray comprising a plurality of spacedsubstantially parallel load bearing elements, each with a plurality ofspaced slots along its length, a plurality of spaced substantiallyparallel cross tie elements with notches spaced along their lengths,said cross tie elements being disposed at substantially right angles tothe load bearing elements and extending through the slots therein, saidslots being wider at a portion thereof to form a wider main portion andgenerally rectangular narrower offset portion whereby the cross tieelements may enter initially through the wider main portion and thendrop into the narrower offset portion as the notches embrace a portionof the load bearing element adjacent the slots in the narrower offsetportion of the slots in a loose interlocking engagement, and keepermeans whose length is short of and out of contact with the next adjacentpri mary elements and which are free of the cross elements secured inthe wider main portion of at least two of the slots for each cross tieelement whereby the cross tie elements are substantially restrained fromremoval from the slots and are simultaneously free to move in looselyinterlocking engagement with the load bearing elements. 5. A reversiblefurnace tray comprising a plurality of spaced substantially parallelload bearing I-beams, each with a plurality of spaced slots disposedalong the web thereof, a plurality of notched spaced substantiallyparallel tie bars disposed at substantially right angles to said beamsand extending through the slots therein, said slots being of generallyL-shaped configuration and wider than the tie bars in an upper portionthereof and narrower than the tie bars in a lower portion thereof, thenotches in. the tie bars being spaced along the lengths thereof atintervals substantially coincident with the slots in the beams wherebythe notches in the notched portions of the tie bars will rest in thenarrower portions of the slots and the tie bar will embrace a portion ofthe I-beam adjacent the slots in the narrower portion of the slots withthe tie bars into a loose fitting interlocking engagement with the beamsin the narrower section of the slots, and keeper means whose length isshort of and out of contact with the next adjacent load bearing I-beamssecured in the wider portion of the slots free of the tie bars in atleast two of said slots for each tie bar whereby the tie bars aresubstantially restrained from vertical movement and hence are held in aloosely interlocking engagement with the beams whereby said beams andtie bars may expand and contract independently of each other,

References Cited in the file of this patent UNITED STATES PATENTS1,140,657 Benjamins May 25, 1915 1,426,736 Hess Aug. 22, 1922 2,710,746Menough June 14, 1955 2,834,267 Beebe May 13, 1958 l l l 1

